Electric gas-discharge tube



Feb. 14, 1950 A. A. PADMOS ET AL ELECTRIC GAS-DISCHARGE TUBE Filed April 27, 1946 INVENTORS ADRIAAN ABRAHAM PADMOS,

PETER SCHOUWSTRA, BY CM-kL-W THEIR ATTORNEY iliary discharge (whose Patented Feb. 14, 1 950 I ELECTRIC GAS-DISCHARGE TUBE Adriaan Abraham Padmos and Pieter Schouwstra, Eindhoven, Netherlands; assignors to General Electric Company, Schenectady, N. Y. 1

Application April 27, 1946, Serial No. 665,386

In the Netherlands Scpteinberil'Y, 1942 Section 1, Public Law 690, August 8, 1946 Patent expires September 17, 19.62

2 Claims. (Cl.i315-334) Electric gas discharge tubes are known comprising two main electrodes and an auxiliary electrode arranged in .the proximity of one of them. This auxiliary electrode and the adjacent main electrode have applied between them such a voltage that they have struck between'them an auxcurrent strength is limited by an impedance connected in series with the auxiliary discharge path) which assists in the production of the discharge between the main electrodes. vFor this purpose, the auxiliary electrode is often connected by a conductor within or on the tube to the distant main electrode. In this case the tube holder need only be arranged in such manner that voltage is supplied to the contact pieces mounted on the tube and connected with the main electrodes; owing to the connection between the auxiliary electrode and the distant main electrode which is provided in or on the tube the auxiliary discharge path is thus automatically put under tension.

In certain cases, for example if the tube is long and is inserted in two tube holders, it is scarcely possible to provide the connection between the auxiliary electrode and the distant main electrode in or on the tube. It might be possible to arrange a contact piece for the auxiliary electrode in the proximity of the contact piece of the main electrode associated with the auxiliary electrode and to provide one of the tube holders with the corresponding contact element and to connect this conductively to that contact element of the other tube holder which corresponds with that contact piece of the second main electrode which is mounted on the tube. V

The disadvantage of this construction is, however, that the tube has always to be so inserted in the tube holders that each tube end-is placed in the tube holder corresponding with that tube end, that is to say the tube cannot be reversed so far as its direction of length is concerned. In addition, care has to be taken that on the tube being inserted in the holders the contact piece of the tube which is connected with the auxiliary electrode does not come into contact with the contact element of the holder intended for the contact piece of the main electrode.

The invention has for its object to avoid these drawbacks. 1

The invention relates to a device containing a gas discharge tube comprising two main electrodes, one auxiliary electrode and an impedance mounted in series with the auxiliary discharge path, the tube being inserted in two tube holders.

The term gas discharge tubes is to be understood to include not only tubes filled with one or more gases but also tubes containing a vapour filling or a gas vapour mixture. I

According to the invention, each tube holder is provided with two contact elements one of which makes contact with the contact piece, mounted on the tube, of a main electrode, and the second contact element of one of thetube holders makes contact with a contact piece, mounted on the tube, of theauxilia'ry electrode, whereas that contact element of each tube holder whichis in contact with a main electrode is conductively connected with that contact elementof the other tube holder which is not in contact with a main electrode. Theelectrodes of the tube are thus always connected correctly whatever may be the position in which the tube is inserted in the holders. This assists in the use of the tube and under certain conditions the possibility of using the tube is also increased.

I In the present case both electrode ends of the discharge tube may be provided with two contact pieces, one of the pieces at one of the ends not being connected to an electrode.

In order that the invention may be clearly understood and readily carried into effect it will now be described more fully With reference to the accompanying drawing, in which one form of construction of the device according to the invention is diagrammatically illustrated.

Referring to the only figure of the drawing, l designates a discharge tube which may be filled with one or more gases, vapours or a gas vapour mixture. The tube I comprises two main electrodes 2 and 3 respectively and an auxiliary elec trade 4. Caps 5 and 6 respectively are mounted on the tube ends. The cap 5 is provided with two contact studs 1 and 8, the stud 1 being connected to the auxiliary electrode 4 with the interposi- "tion of a resistance 9, whereas the stud 8 is in direct connection with the main electrode 2. The resistance 9 serves to limit the current strength of the auxiliary discharge, which may be struck between the auxiliary electrode 4 and the main electrode 2. Instea'd'of a resistance another impedance may be used for this purpose. It is also possible to use a so.-called capacitative auxiliary electrode which may be formed for example by a conductive layer applied to theoutside of the wall of the tube I so as to surround the main electrode 2; this conductive layer is thus connected directly to the stud I and the tube wall under this layer acts at least in part as an impedance for limiting the current strength of the auxiliary discharge with which this part of the tube wall is connected in series.

The cap 6 is also provided with two studs l and H. The stud I 0 is not connected to an electrode of the tube, whereas the stud]! is in direct connection with the main electrode 3.

Associated with the tube I are two tube holders forced against the tube under the action of a 12 and I3 which are provided with identical contact elements [4, I and I6, I! respectively. These contact elements are intended to make contact with the contact studs I, 8 and [0, H respectively of the tube. The contact element M of the tube holder I2 is connected round the tube by means of a conductor 18 to the contact element H of the tube holder [3, said element I! being connected through a conductor l9 to one terminal 20 of a source of alternating current of suitable voltage. The contact element I5 of the holder 12 is connected by means of a conductor 2! to the contact element It of the holder I3. The last-mentioned contact elements are also connected by means of a conductor 22, an impedance 23 suitable for the stabilization of the main discharge and a further conductor '24 to the second terminal 25 of the source of current. Obviously, the device may also com- ;prise a switch to establish or interrupt the con- :nection to the source of current.

On connection, the terminal 25 of the source of current .is connected to the main electrode 2, whereas the terminal 20 is connected to the main electrode 3 and through the conductor [8 also to the auxiliary electrode 4. Thus, in the position shown, the conditions required for normal operation of .the tube are ensured.

In the case of the tube being so connected .to the holders I 2 and [3 that the stud 1 makes contact with the element 15, the stud 3 with the element [4, the stud with the element IT and the stud H with the element t6 the normal working conditions are also ensured since in this .case the terminal 25 is connected via the impedance .23, .the conductor 2|, the contact element 16 of the holder 13 and the contact stud H to the .main electrode .3 and also via the contact element of the holder [2 and the stud -'I to the auxiliary electrode. 4, whilstat the same time the-conductor t9 issuing .from the terminal comes to a dead end iinistud 10 via the element i"! of the holder 13 and on the other end is connected via the conductor IS, the element 14 of the holder l2 and the stud .8 to the main electrode -2.

The tube might also be connected in such manner to the tube holders that the left hand tube end is coupled to the holder 13 and the right hand tube end to the holder 12. In this case, two positions are possible: the upper studs 1 and i0 may come in contact with the upper contact elements 16 and M respectively or else with the lower contact elements I! and 15 respectively. As may directly be ascertained, also in these positions each main electrode is connected to another terminal of the source of current, whereas the auxiliary electrode is con nected to a distant main electrode. The operation of the 'tube is thus perfectly independent of its position relatively'to the holders.

The device is illustrated in the drawing purely spring. The studs 1, 8, l0 and H are all shown located in the plane of the drawing. It is, however, evident that for example the studs I0 and l l jointly with the associated contact elements f6 and H of theholder [3 may also be located in a plane at right angles to the plane of the drawing. It is also possible to mount the studs of the tube, the contact clamps of the holders and the holders sideways from the tube ends normally to the axis of the tube or else normally to the axis of the tube ends concerned.

The presence of the contact stud I0 which is not connected to an electrode of the tube is not indispensable in itself. In the majority of cases, however, it is more convenient for reasons of manufacture to make identical caps, a symmetrical and more stable construction being thus in addition obtained.

What we claim is:

1. A device comprising in combination, a gas discharge tube comprising two main electrodes, an auxiliary electrode, contact studs mounted on "the tube ends and connected to said electrodes and an impedance mounted in series with the auxiliary discharge path, two tube holders engaging the ends of the tube and each provided with two contact elements one of which makes contact with the contact stud of :a main electrodeiand the other of which makes contact with the contact stud of the auxiliary electrode when said :stud is in the holder, 'and means independent of said tube connecting the contact element of each tube holder which is in contact with the main contact stud of a main electrode to the contact element of the other tube holder which is not incontact with thecontact stud of a main electrode whereby said tube is connected correctly in whatever position it .is inserted in said holders with its studs engaging the holder contact elements.

2. A device as claimed in claim 1, wherein both electrode :ends of the discharge tube are provided with two contactzstuds, one contact stud atone of the'ends not being connected to an electrode.

ADRIAAN ABRAHAM PADMOS. PIETER SCHOUWSFIRA.

REFERENCES 01mm) The following references file of this patent:

UNITED STATES PATENTS are of record in the 

